It is no longer done blocking in the multi interface

It did a long time ago

1- Two new error codes are introduced.

CURLE_FTP_ACCEPT_FAILED to be set whenever ACCEPTing fails because of
FTP server connected.

CURLE_FTP_ACCEPT_TIMEOUT to be set whenever ACCEPTing timeouts.

Neither of these errors are considered fatal and control connection
remains OK because it could just be a firewall blocking server to
connect to the client.

2- One new setopt option was introduced.

CURLOPT_ACCEPTTIMEOUT_MS

It sets the maximum amount of time FTP client is going to wait for a
server to connect. Internal default accept timeout is 60 seconds.

Parameters were underquoted, resulting in
warning: AC_LANG_CONFTEST: no AC_LANG_SOURCE call detected in body

Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>

The CURLM_CALL_MULTI_PERFORM reference is an old leftover I had to
remove.

I also added some blurb to the previously blank "sharing" section.

Document the possibility of providing multiple values using the ":"
separator, and the fact that the default value will be ignored if the
option is used.

The default content-type for file uploads is application/octet-stream,
not text/plain as stated in the MANUAL.

Do not try to resolve interfaces names via DNS by recognizing interface
names in a few ways.  If the interface option argument has a prefix of
"if!" then treat the argument as only an interface.  Similarly, if the
interface argument is the name of an interface (even if it does not have
an IP address assigned), treat it as an interface name.  Finally, if the
interface argument is prefixed by "host!" treat it as a hostname that
must be resolved by /etc/hosts or DNS.

These changes allow a client using the multi interfaces to avoid
blocking on name resolution if the interface loses its IP address or
disappears.

This improves portability of the examples.  This patch was
submitted to the OpenBSD ports collection by naddy.

If the option is set to 0, the default timeout will be used - which in
modern libcurl versions equals 300 seconds (== 5 minutes).

Bug: http://curl.haxx.se/mail/lib-2011-12/0051.html
Reported by: Vladimir Grishchenko

Adds a timer based off of CURLINFO_TOTAL_TIME that is used to perform
certain actions after a minimum amount of time has passed using the
progress function. As a consequence the curl handle is now also passed
into the progress function. Progress example now also includes an
example of how to retreive the TOTAL_TIME and print it out.

When the new socket is created for an active connection, it is now done
using the open socket callback.

Test case 596 was modified to run fine, although it hides the fact that
the close callback is still called too many times, as it also gets
called for closing sockets that were created with accept().

Experience has shown that the symbols-in-versions file is very useful to
applications that want to build with a wide range of libcurl versions.
It is however easy to get it wrong and the source gets a bit messy with
all the fixed numerical comparisions.

The point of this script is to provide an easy-to-use macro for libcurl-
using applications to do preprocessor checks for specific libcurl
defines, and yet make the code clearly show what the macro is used for.

prefixing a command with '*' means it is allowed to fail without
aborting the chain actions

Try to be a little more descriptive about the effect of this flag,
rather than parroting what was said in the paragraph just above.

Mention this maximum header size for the header callback cases

shoot, Dan Fandrich already had this pointed out...

Added pop3 username and password example as well as an explanation of
how path part of the URL is used under pop3.

Additionally have corrected a couple of typos.

Multiple auths in the same WWW-Authenticate header

Fixed in commit 7d81e3f7193b8c

This return code has not been used since 7.20.0 so we can stop
mentioning it for current libcurl.

Reported by: Thomas L. Shinnick

Elaborate what max_fd == -1 means

Remove the reference to CURLM_CALL_MULTI_PERFORM as modern libcurl
versions don't ever return that.

This error could be caused by configure scripts being run with -Werror
-Wall, which would lead to libcurl being detected as unusable.

Don't even declare the struct members for disabled features

Introducing the CURLSHE_NOT_BUILT_IN return code for the share interface
when trying to set a sharing option that has been disabled (or not
enabled) in the library.

Previously there was wording that made people uncertain of the exact
rules.

Feedback by: Julien Royer and Georg Lippitsch
URL: http://curl.haxx.se/mail/lib-2011-09/0357.html